Whole-system duct and dryer vent check with before-and-after photos - you see exactly what came out of your vents
That "$99 whole-house special" is a bait ad - the real number appears once they are in your hallway, or the "clean" is a shop-vac at the register. We photograph the inside of your ducts before and after instead.
Fast, Reliable Duct Repair & Sealing Across McLean
Most duct repair calls we take from McLean aren’t about sudden breakdowns. They’re about rooms that never cool evenly, attics that smell musty in July, and energy bills that climbed while the thermostat stayed put. Our crews work McLean weekly, from the estate neighborhoods along George Bush Drive to the wooded lots off Old Dominion Drive and the renovated Colonials near Chesterbrook Woods. Scheduling and dispatch run from our Washington, DC office, and we typically book McLean appointments within a few business days. If you’re noticing weak airflow at a second-floor register or suspect your original ductwork has aged past its useful life, call us at (240) 771-1508 for a free written estimate.
Why CleanRun Air Duct Cleaning Ashburn Is McLean’s Preferred Duct Repair & Sealing Company
We’ve been serving Northern Virginia since 2013, and McLean accounts for a significant share of our duct repair volume. The reason is straightforward: this city’s housing stock presents problems we’ve documented thousands of times, and homeowners here tend to research before they call. They want written prices, photo evidence, and verifiable credentials. We deliver all three on every job.
Our Duct Repair & Sealing in McLean work is backed by the 365-Day Done Right Promise, a written guarantee, not a policy subject to manager approval. Every crew is background-checked and uniformed under Haven Standard Clause 3: Verified Crews. Tomas Reyes, who leads CleanRun, has overseen every McLean job protocol since we opened. We don’t dispatch strangers; we send documented technicians with published license numbers and equipment you can look up yourself.
McLean homeowners receive the same deliverable on every visit: a written scope and price before work starts, and a Documented Photo Record of every duct run, before and after, delivered as part of the standard job record. No exceptions. We’ve completed over 52,000 homes with this exact protocol.
Our Duct Repair & Sealing Services in McLean

Flex Duct Repair
McLean’s flex duct problem is specific and widespread. The 1980s through early 2000s building boom here installed miles of flexible ductwork that has now cycled 25-40 years of Potomac-valley humidity. That moisture load degrades the inner liner, causes fiberglass shedding, and promotes mold colonization at kinks and sags. We find crushed runs draped over joists in unconditioned attics, disconnected collars at plenum take-offs, and sections where the original wire helix has rusted through. Our crew cuts out damaged sections, re-runs with proper support straps and smooth sweeps, and seals with mastic, not tape. A typical flex duct repair in McLean runs $280-$650 depending on linear feet and attic access.

Mastic Sealant Application
Mastic is a thick, brush-applied sealant that outlasts foil tape by decades, and it’s the correct specification for McLean’s climate. The sustained humidity here breaks down tape adhesives in 3-5 years; mastic remains flexible and bonded. We apply it to plenum seams, collar connections, and trunk line joints, particularly on multi-zone systems where a single failed seal can rob an entire zone of designed airflow. In McLean’s 5,000+ square foot estate homes with three or more air handlers, we map every trunk and branch before sealing, so the work is targeted and documented. Mastic sealing for a standard McLean system typically costs $450-$890; larger multi-zone estates range $1,200-$2,400.

Metal Duct Repair
Some McLean properties, especially 1960s-70s cores that survived teardown-and-rebuild cycles, retain original galvanized metal ductwork. These systems corrode at seams, separate at slip joints, and leak conditioned air into unconditioned spaces. We repair with proper sheet metal patches, drive cleats, and sealed joints. Where metal has failed beyond practical repair, we specify replacement with modern insulated flex or rigid duct, always with written options and pricing before work proceeds. Metal duct repair in McLean generally falls between $340-$780.

Duct Insulation Replacement
Original duct insulation in McLean attics and crawl spaces has absorbed decades of humidity. Once the vapor barrier degrades, the fiberglass beneath becomes a mold substrate and thermal liability. We remove deteriorated insulation, treat affected surfaces, and install new foil-faced insulation with proper sealing at all seams. This is particularly critical on supply runs passing through unconditioned attic zones above second-floor bedrooms, where temperature differential is greatest. Duct insulation work in McLean typically ranges $520-$1,100 per system.

What happens when you call
- 1
A real person answersNo phone trees - you reach a local pro.
- 2
You get an upfront price rangeHonest numbers before anyone is dispatched.
- 3
A background-checked tech heads outLicensed & insured, dispatched right away.
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You approve before work beginsNothing starts until you say go.
Before
AfterTrusted Brands We Service in McLean
Our equipment roster includes professional-grade tools from Honeywell, Aprilaire, and Abatement Technologies, brands you can verify independently before agreeing to any work. We stock common McLean replacement parts, including flex duct diameters and mastic formulations sized for the large-volume systems typical of this market. That local inventory means we don’t order-and-wait on standard repairs. For specialized components on multi-zone estates, we source through our Washington, DC office with next-day availability on most items.
Common Duct Repair & Sealing Problems We See in McLean Homes

- Original flex duct from the 1980s-90s renovation era - now kinked, crushed, or disconnected in attic runs, shedding fiberglass liner into supply air. The camera shows it clearly: a fuzzy white coating on the duct interior that wasn’t there when the house was built.
- Fiberglass duct board plenums left untouched during 2000s kitchen and bath remodels - now deteriorating and leaking at seams under decades of Potomac-valley humidity. Homeowners assume renovation meant everything was updated; the ductwork was never touched.
- Multi-zone systems with three or more air handlers where a single failed mastic seal on an attic trunk silently robs airflow from an entire zone. The thermostat reads normal, but the register barely moves a tissue.
- Crushed flex runs in unconditioned attics above second-floor bedrooms - the McLean humidity-mold combination that only becomes obvious when a camera inspection exposes colonized liner on runs serving sleeping areas.
Pricing for Duct Repair & Sealing in McLean, VA
We publish ranges because Haven Standard Clause 1 requires a written price before any work starts. Here is what duct repair and sealing costs in McLean’s market:
| Service | Typical Range in McLean |
|---|---|
| Flex duct repair (single run, standard access) | $280 - $650 |
| Mastic sealant (single-zone system) | $450 - $890 |
| Mastic sealant (multi-zone estate) | $1,200 - $2,400 |
| Metal duct repair | $340 - $780 |
| Duct insulation replacement | $520 - $1,100 |
| Full system assessment with photo documentation | Free |
Factors that move McLean jobs toward the higher end: attic access difficulty (steep roof pitches common in the 1980s Colonial era), multi-zone complexity with three or more air handlers, and the need to navigate finished basement ceilings to reach original plenums. Every estimate includes the full scope in writing before work begins. We also offer a Free Second Opinion on any competitor’s written estimate; bring their quote and we’ll put our number beside it.
Call (240) 771-1508 for your free written estimate.
We Also Serve Cities Near McLean

Our Duct Repair & Sealing crews work throughout Northern Virginia, including Ashburn, Sterling, Herndon, and Leesburg. Each market has distinct housing stock and climate factors; McLean’s large luxury homes and Potomac-valley humidity create repair patterns we don’t see identically elsewhere.
Serving McLean, VA - Our Local Coverage Area
We’re based in the McLean area and know this community well. Use the map below to see our service coverage - if you’re nearby, we can almost certainly help.
FAQs - Duct Repair & Sealing in McLean

McLean sits in the Potomac River valley, which gives it consistently higher ambient relative humidity than Vienna or Reston even a few miles west. That sustained moisture load breaks down tape adhesives and accelerates mold colonization on duct liner surfaces. Combined with McLean’s prevalence of 25-40 year old flex duct from the lobbying-boom building era, the failure rate here is measurably higher than in newer, drier markets. Call (240) 771-1508 for a free assessment and written estimate.
No. We regularly find McLean homes with gorgeous 2010s kitchens and original 1970s fiberglass duct board intact in attic runs. Cosmetic renovation contracts rarely include ductwork replacement, and the deteriorating liner is now shedding glass fibers directly into supply air. The only way to know is a camera inspection, which we include in every free estimate. Call (240) 771-1508 to schedule.
Yes. We use a borescope camera inserted through the register or a temporary access point to inspect the full run. On a 1980s Colonial off Old Dominion Drive, our crew was called because a second-floor bedroom smelled musty every summer. Camera inspection showed a crushed 8-inch flex run draped over a joist in the unconditioned attic, with mold colonizing the liner. We cut out the damaged section, re-ran it with a smooth sweep, and sealed the collar with mastic. Supply air at that register jumped from barely moving a tissue to full flow. The photo record documented everything. Call (240) 771-1508 for a free camera inspection.
We map every trunk and branch before touching anything, then seal in priority order: plenum take-offs first, then trunk seams, then branch collars. Mastic is applied to all accessible joints; where access is limited, we create temporary access panels with written restoration scope. Multi-zone estates in McLean typically require $1,200-$2,400 for complete mastic sealing, with photo documentation of every sealed joint. Call (240) 771-1508 for a written estimate specific to your system layout.
Biannual cleaning is a more defensible recommendation in McLean than in drier DC-area markets because of the Potomac-valley humidity load. The sustained moisture accelerates mold colonization on duct liner surfaces and insulation, particularly in unconditioned attic runs serving second-floor bedrooms. That said, we don’t sell scheduled cleaning to every customer; we recommend it based on what the camera shows and what your system has cycled through. Every recommendation comes with photo evidence and a written scope, not a generic schedule. Call (240) 771-1508 for an honest assessment.
Ready to see what’s actually inside your ductwork? Call (240) 771-1508 for a free written estimate. Every McLean job starts with a documented camera inspection, includes a written price before any work begins, and concludes with a photo record of every duct run, before and after, delivered as a standard deliverable. The 365-Day Done Right Promise applies in writing, not just in marketing copy.
Written by Tomas Reyes, Owner at CleanRun Duct Repair & Cleaning, serving McLean and Northern Virginia since 2013.




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